[Galaxy S III Q&A, Help & Troubleshooting] KuBi4K:
Hi everyone !

I'm new here (and not a native english speaker, so apologies in advance for any grammar mistakes)

Before making this thread, I looked for info here, but I'm not sure for what to search.

I'll try to explain my problem here.

I bought a Galaxy SIII from my provider 3 weeks ago and everything looked fine, till last week.

Some times to time, with no apparent reason or cause, while my phone is on sleep mode, on my desk, or in my pocket, playing music, I have the following problem: when I push the on/off button to wake up my phone, my screen is turning on, taking me to the lock screen.

But, my screen brightness is very low, like set to the minimum.

And when I draw my unlocking pattern, screen goes black.

Bottom buttons are lit and my phone seems to be OK, I can feel haptic feedbacks.

But the screen is black.

If I push the on/off button again, screen stays black and bottom buttons are not lit anymore, as a usual Sleep Mode.

If I push on/off again (depending on how much I wait between 2 on/off):

- My phone awakes from Sleep and takes me again to the unlock screen, brightness still very low. And after the unlocking pattern traced, black screen again

- If I didn't wait enought after putting it into sleep mode, in this case, I don't have to redraw the unlocking pattern. I'm back to my home screen...

for 1/4 of a second, stilll with brightness at the minimum. And screen goes black.

And after a serie on onoffonoff, boom, my screen is back to full and normal brightness and everything is OK.

At the beginning, my phone did that once in a while. I thought at the time ti was after pushing the on/off button while using a CPU/RAM hungry app, my phone struggling to recover....

But now, it's totally random.

Depending on .... I don't know what, I have to do the onoffonoff thing 2, 5, 10, 50 times in a row so my phone can recover from is half comatose.

Yesterday, I could not use my phone for half an hour ...

and if someone calls me, I hear the ringtone, but screen stays black.

I can answer the call (but not knowing who's calling) by sliding on the part of the screen where the slider normally is.

Funny thing is about removing the battery. It doesn't solve my problem.

When I do so, my phone boots, I see the "Samsung Galaxy SIII" boot screen, on low brightness (whih is not normal ...)

After that, I normally have another boot screen with my provider's logo and tone. But screen goes black again (but I still here the tone)

Then I realized it started to happen when my phone proposed me a Samsung update.

I tried to reset my phone to factory settings but it didn't work, the update was still here.

For a while I thought my problem was solved, because my phone behaved normally for 3 or 4 hours, without problem.

But it came back.

I found on the internet several "almost-same-problems" without proposed solutions.

Like checking if the proximity sensor was blocked by a protective transparent plastic sheet, or a case.

I tried to to remove mine.

Didn't work.

Some people said it was linked to their phone trying to acquire a wifi network.

My wifi on or off, withiin or without the range of a wifi router didn't work ...

I tried to note things down about what I did, when, how, app launched before the problem appears.

I checked battery info (temp, voltage, etc).

No pattern emerged.

So.

Hs anyone of you enountered the same problem ?

Do you have ideas, solutions I can use ?

Or maybe a voodoo prayer ?

I could sent it back to my provider which will bounce it back to Samsung. But it will take ages (3 to 4 weeks ...) :'(

Thanks in advance !